Paper bag

ABSTRACT

The invention relates to a paper bag for packaging of bulk material, having a standing bottom ( 2 ) and a valve bottom ( 3 ), a front wall ( 4 ) and a rear wall, the front wall and the rear wall being glued to each other in overlapping relationship, the paper bag further comprising cover sheets ( 5, 5 ′) for closing the standing bottom ( 2 ) and the valve bottom ( 3 ), wherein the cover sheet ( 5 ) of the standing bottom ( 2 ) and/or of the valve bottom ( 3 ) is provided with a tear open strip ( 6 ) which extends across the entire length of the bottom. It is characterized in that a foil ( 9 ) is placed below the standing bottom cover sheet ( 5 ) and/or below the valve bottom cover sheet ( 5 ′) and is removably glued to the paper bag ( 1 ) in such a manner that after tearing open of the standing bottom cover sheet ( 5 ) and/or of the valve bottom cover sheet ( 5 ′) the foil ( 9 ) still closes the paper bag ( 1 ) completely and sets the product free only after peeling off said foil.

BACKGROUND OF THE INVENTION

The invention relates to a paper bag according to the description herein.

Paper bags are usually provided as valve bottom bags or block bottom bags for storing bulk material, having a standing bottom, a valve bottom, a front wall, a rear wall and a valve tube inserted in the valve bottom to be mounted onto the filling nozzle of a filling device, wherein said valve tube may be closed by turning it over or in case of thermo-material to be heat sealed. Such a valve bottom bag is for example known from the German Utility Patent DE-20 2005 004 750 U1.

Valve bottom bags are principally equipped with cover sheets in order to protect the folded and glued bottoms, i.e. the standing bottom and the valve bottom, from coming undone accidentally. A cover sheet is a paper strip or slip which is glued to the bottoms of the paper bag. Most cover sheets are smaller than the bottom and normally glued not only to the bottom, but also to the valve tube protruding laterally from the bottom. However, it is already known as well to extend the cover sheets over the edges of the standing bottom and the valve bottom up to the region of the front wall and the rear wall of the paper bag.

In order to open the paper bag filled with bulk material, the cover sheet has been traditionally torn off the standing bottom, the disadvantage being, however, that paper fibres could fall into the product—a fact that is not tolerated in every case. In this context, it is also already known to provide the cover sheet with a tear-open strip as to the German Patent Publication 1 761 750 for an easier tear-off.

SUMMARY OF THE INVENTION

The object of the invention is to further modify a paper bag with tear-open strip, so that no paper fibres can get into the product when torn open.

As a solution to this object, a foil is placed below the standing bottom cover sheet and/or below the valve bottom cover sheet of a paper bag as mentioned above which is removably glued to the paper bag in such a manner that after tearing open of the standing bottom cover sheet or of the valve bottom cover sheet the foil still closes the paper bag completely and sets the product free only after peeling off said foil.

Both bottom parts may thus be unfolded after tearing open of the standing bottom with the bag still remaining closed for the time being due to the foil. Thus, no paper fibres can fall into the product. The bag is opened only when the foil is grabbed at one edge and torn off the paper and the product can now be accessed freely.

The foil may be a plastic foil, a metal foil, a coated or uncoated paper foil, a fibre glass foil, a woven foil or a spunbonded foil made of woven fibres. In addition, the foil material should be biodegradable, compostable or recyclable if necessary.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is hereinafter further illustrated by means of the accompanying drawings, wherein:

FIG. 1 shows a top view of a paper bag having a standing bottom, a valve bottom and a valve tube;

FIG. 2 shows a schematic illustration of the standing bottom when being torn open;

FIG. 3 shows the torn open and unfolded standing bottom compared to FIG. 2 and which is still closed by a foil;

FIG. 4 shows the initial stage of peeling off the foil, wherein the standing bottom is unfolded compared to FIG. 3;

FIG. 5 shows the already partially-opened paper bag compared to FIG. 4;

FIG. 6 shows the paper bag of FIG. 3 with further features;

FIG. 7 shows a paper bag in accordance with a second preferred embodiment of the present invention;

FIG. 8 illustrates a plan view of a complete, empty bag according to the present invention;

FIG. 9 schematically illustrates the open standing bottom of the bag according to FIG. 8;

FIG. 10 schematically illustrates applying adhesive to the open standing bottom of the bag;

FIG. 11 schematically illustrates affixing a foil to the bottom of the bag;

FIGS. 12 and 13 schematically illustrate folding side flaps to close the standing bottom of the bag;

FIG. 14 is a partial plan view illustrating the standing bottom with the side flaps closed;

FIG. 15 schematically illustrates securing a cover sheet upon the standing bottom of the bag;

FIG. 16 illustrates the finished standing bottom of the bag;

FIG. 17 schematically illustrates a first step in opening the standing bottom of the bag;

FIG. 18 schematically illustrates a second step in opening the standing bottom of the bag;

FIG. 19 illustrates the standing bottom of the bag with the cover sheet torn open;

FIG. 20 schematically illustrates a third step in opening the standing bottom of the bag;

FIG. 21 schematically illustrates a fourth step in opening the standing bottom of the bag;

FIG. 22 schematically illustrates a fifth step in opening the standing bottom of the bag; and

FIG. 23 illustrates the completely-opened standing bottom of the bag.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Identical parts in the figures are referenced with like numerals. Thus FIG. 1 shows a paper bag 1, having a standing bottom 2 and a valve bottom 3 which are folded in a manner known per se as star seal bottoms or block bottoms and which are each covered by a cover sheet 5, 5′. In the illustrated embodiment, the cover sheets 5 and 5′ extend over the edges of the standing bottom 2 and the valve bottom 3 up to the region of the front wall 4 and the rear wall and are glued to the paper bag 1 in the usual way.

Further, a valve tube 7 is incorporated into the valve bottom 3 in the illustrated embodiment as it is known in the art, e.g. from the Utility Model Document DE 20 2005 004 750 U1.

In FIG. 1 the paper bag 1 is represented in such a way that the standing bottom 2 is directed upwards as this may be favourable for tearing open a paper bag 1 filled with products. A tear-open strip 6 is provided for tearing open the paper bag which extends across the entire length of the standing bottom 2 and thus from one side of the cover sheet 5 to the opposite other side.

FIG. 2 now shows the procedure of tearing open the standing bottom cover sheet 5 in a schematic illustration, wherein only the upper part of the paper bag 1 is represented with front wall 4 and one side wall. For this purpose, the tear-open strip 6 near the side wall 8 is grabbed and pulled in the direction of the arrow to the opposite side wall 8′.

FIG. 3 shows the paper bag 1 with the cover sheet 5 fully torn open and unfolded side strips 5″, wherein the paper bag 1 is, however, still closed by a placed plastic foil 9 that is removably glued to the cover sheet side strips 5″.

In order to open the paper bag 1, foil 9 needs to be separated from the side strips 5″, which is indicated in FIG. 4, by grabbing one edge 10 of the foil 9 and peeling said edge off the cover sheet side strip 5″. The product has not yet been set free at this stage, since the interior of the paper bag 1 is still closed.

Only FIG. 5 shows the foil 9 which has been further peeled off and which now sets free the interior 11 of the paper bag 1. As soon as the foil 9 has been fully peeled off the paper bag 1, the product located in the interior 11 can be accessed freely without having been contaminated by paper fibres upon opening.

FIG. 6 shows a further modification of the invention, in which the foil 9 is provided with a device for re-closure. In a first variant, the device for re-closure is embodied by the application of special glue or special paste due to which the foil 9 may be removed from the paper bag 1 and reattached as often as required. Such special glues or special pastes are known to the person skilled in the art. For this purpose, glue lines along the edge of foil 9 may be provided or else the entire foil 9 may be coated with such special glue.

In another variant, a closure 13 is provided on the inside of the side strips 5″ of the paper bag 1, said closure being located in one embodiment below the foil 9 which is not bonded in that region, whereas in another embodiment the foil 9 is smaller and does not extend to the edges of the side strips 5″, but spares a strip, in which both parts 13′, 13″ of the closure 13 are disposed. In one embodiment, the closure 13 is a snap lock with groove and tongue, in another embodiment it is a hook-and-loop fastener. Snap locks with groove and tongue are well known from plastic bags and thus known to the person skilled in the art. The same is true for the aforementioned hook-and-loop fastener. To reclose the bag, the side strips 5″ of the torn open cover sheet 5 are pressed towards each other after the foil 9 has been peeled off, thus causing the tongue 13′ to engage with the groove 13″ of the closure 13. A hook-and-loop fastener is closed in a similar way, namely by pressing its two parts towards each other. The once opened paper bag 1 may thus be easily re-closed.

The foil 9 of the invention may be printed or blank. Furthermore, it may be provided with safety features, such as pictures, holograms or stripes, ensuring that the foil 9 is marked as damaged once it has been peeled off or removed from paper bag 1. In addition to the mentioned safety features, the foil may also be provided with information on the content of the product or with instructions on how to handle the paper bag or the product contained therein.

In another embodiment of the invention, the foil 9 may serve to form a distribution device together with the inwards folded bottom, wherein the foil 9 is advantageously not glued to the paper bag 1 in the region and in the vicinity respectively of one of the side walls 8 or 8′. Although the foil 9 covers the interior of the paper bag 1 in this region, it may, however, be manually turned up after tearing open the tear-open strip 6, as illustrated in FIG. 2, so that the turned up part of the standing bottom 2 can be grabbed manually and pulled outwards in the direction of the side wall 8 or 8′.

Moreover, when the turned up part of the standing bottom 2 is provided with incisions running for example parallel to the front wall 4 up to the side wall 8 or 8′, the turned up part of the standing bottom 2 may then be manually pulled outwards, and forms together with the part of the loose foil 9 that had previously been turned up in the other direction a distribution device which is especially useful when the bottom opposing the standing bottom 2, described as valve bottom 3 in one embodiment according to FIG. 1, has a handle. A user may then grab the handle comfortably and empty the product by the distribution device which is formed by the turned up foil 9 and the pulled out standing bottom region.

The foil 9 may furthermore be provided with recesses 14, 14′ near the side edges 8 or 8′ in the form of holes or punchings that allow the foil 9 to be hung up alone or together with the opened paper bag 1, e.g. to a nail or to a hook. This is particularly favourable when the foil is provided with instructions for use that may assist the user in recycling the product after removing the foil from the paper bag 1.

A second preferred bag is illustrated in FIG. 7. As shown in FIG. 7, a paper bag 101 may be provided with a handle 115 on the cover sheet 105, 105′ of the standing bottom 102 and/or the valve bottom 103 which runs parallel to the tear-open strip 106. In case the handle is disposed in the centre of the bottom, however, the tear-open strip 106 does not run centrically to the cover sheet 105, 105′.

As shown in FIG. 8, the standing bottom 2 and the valve bottom are both flapped onto the front wall 4 of the empty paper bag 1. The valve bottom 3 is covered with a valve bottom cover sheet 5′ and includes a valve tube 7. The standing bottom 2 is covered with a standing bottom cover sheet 5 which includes a tear-open strip (dashed line). The standing bottom cover sheet 5 is transparently illustrated in FIG. 8 for comprehension.

FIG. 9 shows an open standing bottom 2 with corner folds 28 located at the end portions of the bottom 2 and side flaps located at the sides of the bottom 2. In the course of manufacturing the paper bag 1, the side flaps 25 are folded around the folding lines 26. A frame 91 of an adhesive, preferably re-adherable, is applied as shown in FIG. 10 for ultimately affixing the foil 9 and reliably closing the open region of the standing bottom 2 as illustrated in FIG. 11.

The side flaps 25 are then folded along the flap folding lines 26 as illustrated in FIGS. 12 and 13, with one side flap overlapping on top of the other side flap. As shown in FIG. 14, the foil 9 situated underneath the folded side flaps 25 is not completely covered and partially protrudes in the regions of the corner folds 28. The cover sheet 5 having a tear-open strip 6 is then secured to the folded flaps 25 upon glue strips 51 as shown in FIG. 15. FIG. 16 illustrates the finished standing bottom 2 of the bag 1 with the cover sheet 5 and tear-open strip 6 covering the standing bottom 2.

FIGS. 17 and 18 schematically illustrate the first steps in opening the standing bottom by tearing apart the cover sheet 5 by pulling the tear-open strip 6 thereacross. FIG. 19 illustrates the tear-open strip 6 completely severed such that the cover sheet 5 is completely split open by a slit 61 dividing the cover sheet into two cover sheet side strips 5″. It is now possible to easily grab with the fingers of one hand underneath the upper side flap and open the standing bottom by first ripping and flapping open the upper side flap and then ripping and flapping open the lower side flap in reverse order to FIGS. 12 and 13 supra.

As shown in FIG. 16, the tear-open strip 6 is aligned with an upper longitudinally-extending edge of the upper side flap 25. This enhances access upon severing the tear-open strip 6 by facilitating inserting fingers under the upper side flap 25 and pivoting or flipping this upper side flap 25 to the open position. The lower side flap can then be easily pivoted or flipped open by inserting fingers thereunder. Each side flap 25 has a width substantially greater than one-half the width of the finished standing bottom 2, thereby allowing these side flaps 25 to overlap one another. In a preferred embodiment, the side flaps 25 overlap one another by about 3-4 cm.

FIG. 20 illustrates the standing bottom 2 with the foil 9 still covering the opening in the bottom, with FIG. 21 illustrating start of opening of the bottom 2 by peeling off the foil 9 starting at a corner portion 92 of the foil and FIG. 22 illustrating the foil 9 further peeled off. Finally, FIG. 23 illustrates the opened bottom 2 with the foil 9 almost entirely peeled off and adhering to just a single edge of one of the side flaps.

The preceding description of the present invention is merely exemplary, and not intended to limit the scope thereof in any way. 

What is claimed is:
 1. A paper bag (1) for packaging bulk material, comprising a bag body including a standing bottom (2) and valve bottom (3) at opposite ends thereof, and a front wall (4) and rear wall extending between the standing (2) and valve (3) bottoms and coupled to each other in overlapping relationship, said front (4) and rear walls together defining an interior of the bag (1), each of said standing bottom (2), valve bottom (3) front wall (4) and rear wall comprising paper, a separate single cover sheet (5) closing said standing bottom (2) and affixed to both said front (4) and rear walls, said cover sheet (5) having a tear-open strip (6) spaced from the front (4) and rear walls and extending across an entire length of said standing bottom (2), said front (4) and rear walls extending into two diametrically-opposed side flaps (5″, 5″) inwardly folded towards one another to be situated underneath said separate cover sheet (5) and tear-open strip (6), such that upon severing the tear-open strip (6), each said flap (5″, 5″) is upwardly and outwardly pivotal from said respective front (4) and rear walls to unfold said bottom, said cover sheet (5) comprising paper such that severing the tear-open strip (6) releases loose paper fibers, and a foil (9) removably secured to the front (4) and rear walls of the bag body to cover an opening into the interior of the bag (1) at the standing bottom (2) and also removably affixed to sides of said respective flaps (5″, 5″) opposite to the sides of said flaps (5″, 5″) bordering said separate cover sheet (5) when folded inwardly, said foil (9) remaining affixed to said bag (1) and said respective side flaps (5″, 5″) upon severing the tear-open strip (6) and unfolding said respective side flaps (5″, 5″), and said foil being peelable off said side flaps (5″, 5″) and bag body to expose the bag interior, after said tear-open strip (6) is severed and said respective side flaps (5″, 5″) pivoted.
 2. The paper bag according to claim 1, wherein the bag body additionally comprises side walls (8, 8′) interconnecting said front (4) and rear walls and extending between the standing (2) and valve (3) bottoms, with said foil (9) additionally removably affixed to said side walls (8, 8′) said tear-open strip (6) extending across said standing bottom (2) in a direction between said side walls (8, 8′) such that the tear-open strip (6) is severable by being pulled in a direction from one of said side walls (8, 8′) to an opposite side wall (8, 8′), and said foil (9) also remaining affixed to said side walls (8, 8′) upon severing the tear-open strip (6), and being peelable off said side flaps (5″, 5″) and side walls (8, 8′) to expose the bag interior, after said tear-open strip (6) is severed and said side flaps (5″, 5″) upwardly and outwardly pivoted.
 3. The paper bag according to claim 2, wherein said side flaps (5″, 5″) overlap one another underneath said separate cover sheet (5) and tear-open strip (6) when folded inwardly.
 4. The paper bag according to claim 1, wherein said foil comprises plastic.
 5. The paper bag according to claim 1, wherein said foil comprises metal.
 6. The paper bag according to claim 1, wherein said foil comprises a coated paper or a paper foil.
 7. The paper bag according to claim 1, wherein said foil comprises a fiber glass foil, a woven foil or a spunbonded foil made of woven fibers.
 8. The paper bag according to claim 1, wherein said foil comprises a biodegradable, compostable or recyclable material.
 9. The paper bag according to claim 1, wherein said side strips cooperatively include a closure device disposed along the tear-open edges of the side strips.
 10. The paper bag according to claim 1, wherein said paper bag body further includes a pair of opposite side walls, said closure device comprises a snap lock and said snap lock including a groove and a tongue each extending from one side wall to the other side wall.
 11. The paper bag according to claim 10, wherein said closure device comprises a hook-and-loop fastener extending from one side wall to the other side wall.
 12. The paper bag according to claim 1, wherein said foil is fully-coated or coated within a region on a bottom side thereof with re-adherable adhesive.
 13. The paper bag according to claim 1, wherein said foil comprises at least one recess defined therethrough.
 14. The paper bag according to claim 1, wherein said foil is provided with safety features to evidence tampering or damage.
 15. The paper bag according to claim 1, wherein said cover sheet includes a handle, sand handle extending generally parallel to the tear-open strip, said tear-open strip being disposed away from a center of the cover sheet.
 16. The paper bag according to claim 14, wherein said safety features comprise pictures, holograms, and/or strips operable to indicate foil damage resulting from peeling off the foil away from the paper bag.
 17. The paper bag according to claim 1, wherein said foil is printed with indicia.
 18. The paper bag according to claim 17, wherein said indicia comprise contents and/or instructions. 